Adds a warning when identical expressions are found on both the true and false branches of ?:. This is another common copy-paste error.
Signed-off-by: Chris Forbes <chrisf@xxxxxxxxx>
---
evaluate.c | 8 +++++++-
validation/check_identical_exprs_on_cond.c | 13 +++++++++++++
2 files changed, 20 insertions(+), 1 deletions(-)
create mode 100644 validation/check_identical_exprs_on_cond.c
diff --git a/evaluate.c b/evaluate.c
index 11de7aa..c339e63 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -898,7 +898,7 @@ static int expr_list_equiv(struct expression_list *lhs,
int expr_equiv(struct expression *lhs, struct expression *rhs)
{
/* recursively determine if lhs ~ rhs. */
- if (!lhs ^ !rhs) return 0;
+ if (!lhs || !rhs) return 0;
if (lhs->type != rhs->type) return 0;
if (lhs->flags != rhs->flags) return 0;
@@ -1220,6 +1220,12 @@ static struct symbol *evaluate_conditional_expression(struct expression *expr)
const char * typediff;
int qual;
+ if (!preprocessing) {
+ if (expr_equiv(expr->cond_true, expr->cond_false))
+ warning(expr->pos, "identical expressions on both "
+ "branches of '?:'");
+ }
+
if (!evaluate_conditional(expr->conditional, 0))
return NULL;
if (!evaluate_expression(expr->cond_false))
diff --git a/validation/check_identical_exprs_on_cond.c b/validation/check_identical_exprs_on_cond.c
new file mode 100644
index 0000000..85a9938
--- /dev/null
+++ b/validation/check_identical_exprs_on_cond.c
@@ -0,0 +1,13 @@
+extern void bar(void);
+
+static void foo(void *a, void *b, void *c)
+{
+ void * d = a ? b : b; /* should warn */
+}
+/*
+ * check-name: A warning should be issued for identical expressions on both the true and false branches of the '?:' operator.
+ *
+ * check-error-start
+check_identical_exprs_on_cond.c:5:22: warning: identical expressions on both branches of '?:'
+ * check-error-end
+ */
--
1.7.4.1
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